1. Field of the Invention
The present invention relates to a liquid crystal display device and a fabricating method thereof, and more particularly to a transflective type color filter substrate that increases the color gamut of a transmission area and brightness of a reflection area, and a fabricating method thereof.
2. Discussion of the Related Art
Generally, a liquid crystal display device LCD has liquid crystal cells arranged in a matrix shape in a liquid crystal display panel to control the light transmittance of the cells in accordance with a video signal to display a picture.
The liquid crystal display devices may be classified as transmission types and reflection types in accordance with the presence or absence of a light source. The transmission type liquid crystal display device transmits light from a backlight unit that is installed at the rear surface of a thin film transistor array substrate facing a color filter substrate with a liquid crystal therebetween to a display surface, thereby realizing a picture. The reflection type liquid crystal display device reflects an external light or a separate auxiliary light that is incident upon a lower substrate through an upper substrate to the display surface by use of a reflection plate formed on the thin film transistor array substrate thereby realizing the picture.
A transflective type liquid crystal display device has been proposed that takes advantages of both the transmission type and the reflection type display. The transfelective type liquid crystal display device operates in a reflection mode if the external light is sufficient and in a transmission mode by use of a backlight unit if the light is insufficient. Accordingly, the transflective type liquid crystal display device can reduce power consumption as compared to the transmission type liquid crystal display device and does not require an external light source like the reflection type liquid crystal display device.
The transflective type liquid crystal display panel shown in FIG. 1 includes a thin film transistor substrate 60 where a thin film transistor array is formed, and a color filter substrate 50 where a color filter array is formed.
On the color filter substrate 50, the color filter array having a black matrix for preventing light leakage, a color filter 42 for realizing color and a common electrode 46 that forms a vertical electric field with the pixel electrode are formed on an upper substrate 11.
On the thin film transistor substrate 50, the thin film transistor array having a gate line crossing a data line, a thin film transistor formed at the crossing of the gate and data line, a pixel electrode 22 formed in a pixel area connected to the thin film transistor, and a reflection electrode 30 formed in a reflection area of the pixel area are formed on a lower substrate 1.
The reflection electrode 30 reflects the external light that is incident through the color filter substrate 50, to the color filter substrate 50. An organic film formed under the reflection electrode has an embossed surface, and the reflection electrode thereon also has the embossed shape, thus reflection efficiency is increased by a dispersion effect.
The pixel electrode 22 generates a potential difference with the common electrode 46 by a data signal supplied through the thin film transistor. The potential difference causes a liquid crystal to rotate and the light transmittance is determined in accordance with the degree of rotation of the liquid crystal in each of the reflection area and the transmission area.
In case of the transflective type liquid crystal display panel, reflection light RL incident upon the reflection area is reflected at the reflection electrode 30 through a liquid crystal layer and emitted through the liquid crystal layer, as shown in FIG. 1. Transmission light TL from a backlight unit 40 that is incident upon the transmission area is transmitted through the liquid crystal layer and emitted to the outside.
In this display, the reflection light RL of the reflection area passes through the color filter 42 twice, but on the other hand the transmission light TL of the transmission area passes through the color filter 42 once, thus there is a color difference between the reflection area and the transmission area. At this moment, if the picture is realized on the basis of the color filter of the reflection area, the color gamut deteriorates more in the transmission area than in the reflection area. If the picture is realized on the basis of the color filter of the transmission area, the color gamut of the transmission part is improved, but there is a problem in that the brightness of the reflection area deteriorates.